This core component is composed of laboratory facilities, equipment, and services that will be utilized by the proposed program. The core is service-oriented in concept. Its objective will be to provide in a timely, efficient, and cost-effective manner the in vivo evaluation of the antitumor activity of candidate drugs that may be at various stages of development in the proposed program. Evaluations may range from an initial assessment of in vivo antitumor activity to detailed evaluations in support of an IND application (e.g., dose and treatment schedule optimization). Data will be presented in terms of clinically relevant endpoints (e.g., cures, regressions, or prolonged time to treatment failure). Dose-response relationships will be assessed in all studies. Use of these data in drug development decision-making will be a cooperative effort among the core component leader, the individual project leaders, and the program PI.